There are two aspects that are part of English grammar: the continuous and the perfect. Other aspects are possible, but they are a part of English semantics rather than English grammar. The grammar has a catch-all indefinite aspect construction which is used for most of these other possibilities, such as the habitual aspect, the eternal aspect, or the periodic aspect.
Your sentence uses one of these semantic aspects that fall outside of grammar. The meaning of the word "always" suggests something like the eternal aspect.
For that suggestion to make sense, the grammar of the sentence should display the indefinite aspect. The continuous construction is in conflict with the meaning of the word "always".